Refactored test code a lot. Introduced KotlinLibTest.

translator/test/org/jetbrains/k2js/test/KotlinLibTest.java

@@ -45,6 +45,7 @@ public class KotlinLibTest extends TranslationTest {
     public void kotlinJsLibRunsWithRhino() throws Exception {
         Context context = Context.enter();
         Scriptable scope = context.initStandardObjects();
+        //
         runFileWithRhino(kotlinLibraryPath(), context, scope);
         Context.exit();
     }